An object with a mass of 8 kg is on a ramp at an incline of pi/8 . If the object is being pushed up the ramp with a force of 7 N, what is the minimum coefficient of static friction needed for the object to remain put?

1 Answer
Mar 18, 2018

Total force acting on the object downward along the plane is mg sin ((pi)/8)=8*9.8* sin((pi)/8)=30N

And applied force is 7N upward along the plane.

So,net force on the object is 30-7=23N downwards along the plane.

So,static frictioanl force that needs to act to balance this amount of force should act upwards along the plane.

Now,here,static frictional force that can act is mu mg cos ((pi)/8)=72.42mu N (where, mu is the coefficient of static frictional force)

So,72.42 mu =23

or, mu=0.32